It is three years since Rafael Nadal went beyond the fourth round at Wimbledon, a year in which he reached the final only to lose out to an inspired Novak Djokovic. His shock defeat to the Australian teenager Nick Kyrgios on Tuesday was his third straight early defeat and, inevitably, people will wonder whether at the age of 28 we have seen the best of Nadal at Wimbledon?

In some ways, if that’s true, it’s not a surprise. As Nadal has pointed out a few times over the past fortnight, he reached five straight finals between 2006 and 2011 – he didn’t play in 2009 – winning the title twice, in 2008 and 2010. That was when he was at his most dominant elsewhere, romping to French Open titles and winning in Australia (2009) and at the US Open (2010).

Of course, he added another US Open title in 2013 and won his ninth French Open title in Paris last month, so it’s always a surprise when Nadal loses before the semi-finals. But on grass, a surface he took time to come to terms with and which is the toughest for his knees in terms of bending, he is more vulnerable than elsewhere.

A couple of months ago, Nadal said we ought to “get used to” him losing in the early rounds. It was a comment that says a lot about how Nadal thinks and explains a little of why he has been so successful; he is always prepared for a fight, never takes anyone lightly and understands that on any given day, anything can happen. He didn’t play badly against Kyrgios, but he didn’t take his chances, something that when he was under pressure in the early rounds in previous years, he managed to do. On grass, more than anywhere else, matches can be decided on a handful of points.

It’s true – and always been the case – that on grass Nadal is vulnerable to big servers and those players who can hit hard and flat. The surface gives that kind of player an obvious advantage and it’s not quite so easy for Nadal to show his outstanding defensive skills. The ball doesn’t get up as high, negating some of the effect of his top-spin forehand, and without a huge serve like Kyrgios, he gets fewer free points than the likes of Djokovic, Andy Murray and Roger Federer.

Winning the French Open and Wimbledon back to back is an incredibly difficult thing to do. Nadal’s done it twice but before him, you have to go back to Bjorn Borg in 1980 to find the last man to double up. Borg also did it in 1978 and 1979 but before that only Rod Laver, in the Open era, has managed it.

Though Nadal said winning this year’s French Open was less physically demanding than most, the buildup to Roland Garros was stressful, losing his Monte Carlo crown and going out early in Barcelona. He won in Madrid but lost to Djokovic in the final in Rome, so getting himself to the point where he could win again in Paris took an awful lot of emotional and mental effort.

In 2012 and 2013, the effort of winning in Paris took a physical toll on Nadal and his knees gave out when arriving at Wimbledon. This year, he was physically better and as always, he competed hard. But that stress of winning in Paris is likely to become greater, especially with the passing of time. Nadal will be 29 when he arrives in London next summer and he’s been on tour since he was 16.

With the likes of Grigor Dimitrov, Milos Raonic and now Kyrgios beginning to come through, Nadal may find it tougher and tougher at Wimbledon in the future and the days of back-to-back finals are probably over. But there has probably never been a better competitor in the sport and it would be no surprise at all if we see Nadal in the final one more time.